Fish Population Structure in Arctic Lakes

1978 ◽  
Vol 35 (1) ◽  
pp. 53-59 ◽  
Author(s):  
G. Power
Keyword(s):  
Population Structure ◽  
Life Span ◽  
Lake Trout ◽  
Age Determination ◽  
Salvelinus Namaycush ◽  
Fish Population ◽  
Arctic Lakes ◽  
Fish Populations ◽  
Coregonus Clupeaformis ◽  
Large Fish

Existing theories attempting to account for the predominance of older, larger individuals and the often observed bimodal character of the length-frequency distribution of unexploited northern fish populations were evaluated and rejected. The error in interpretation appears to result from problems in age determination of northern lake trout (Salvelinus namaycush) and lake whitefish (Coregonus clupeaformis). An alternative explanation of the observed structure of arctic lake fish populations is proposed. Growth of fish in these populations is relatively rapid until first maturity, when it becomes slow through a life span that may exceed 50 yr. Mortality declines rapidly through early life and stabilizes at a very low level through much of the life span. The combination of these growth and mortality patterns produces a population containing many small, few intermediate, and many large fish. Selection by gill nets provides a unimodal sample of large fish or a bimodal sample of large and smaller fish from such populations. A model is developed to demonstrate this and compared with results obtained from several northern Quebec lakes. Key words: Salvelinus namaycush, Coregonus clupeaformis, age, population structure, arctic lakes

Changes in fish populations affected by the construction of the La Grande complex (Phase I), James Bay region, Quebec

1995 ◽  
Vol 73 (10) ◽  
pp. 1860-1877 ◽  
Author(s):  
Jean-Claude DesLandes ◽  
Sylvie Guénette ◽  
Yves Prairie ◽  
Réjean Fortin ◽  
Dominique Roy ◽  
...  
Keyword(s):  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Time Intervals ◽  
Complex Phase ◽  
Coregonus Artedii ◽  
Secondary Productivity ◽  
Longnose Sucker ◽  
The Impact

Catches per unit of effort (CPUE) with experimental gill nets, recruitment, growth, and condition were monitored between 1977 and 1992 to evaluate the impact of impoundment on the main fish species of La Grande 2, Opinaca, and Caniapiscau reservoirs and the Boyd–Sakami diversion. CPUE and recruitment of northern pike (Esox lucius) and lake whitefish (Coregonus clupeaformis) increased markedly at most stations after impoundment and decreased at the end of the series. The lake whitefish and cisco (Coregonus artedii) showed their most striking rise in CPUE at two bay stations of La Grande 2 and Opinaca reservoirs. CPUE and recruitment of the longnose sucker (Catostomus catostomus), white sucker (Catostomus commersoni), and lake trout (Salvelinus namaycush) (Caniapiscau) showed a general decrease following impoundment. CPUE for the walleye (Stizostedion vitreum) also decreased at several stations; however, the two most southerly stations in La Grande 2 reservoir and the Boyd–Sakami station showed high CPUE during the series. Concentration–redistribution phenomena explain part of the observed variations in CPUE. Correlation analyses showed that walleyes and white suckers were attracted to the warmer, more turbid stations, and that the high primary and secondary productivity of bay stations attracted the coregonines. Growth and condition of the main species increased during variable time intervals after impoundment and decreased at the end of the series.

Accumulation, distribution and toxicology of dietary nickel in lake whitefish (Coregonus clupeaformis) and lake trout (Salvelinus namaycush)

2001 ◽  
Vol 130 (2) ◽  
pp. 145-162 ◽  
Author(s):  
M.D Ptashynski ◽  
R.M Pedlar ◽  
R.E Evans ◽  
K.G Wautier ◽  
C.L Baron ◽  
...  
Keyword(s):  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish

Fecundity Changes in Exploited Populations of Lake Whitefish (Coregonus clupeaformis) and Lake Trout (Salvelinus namaycush)

1978 ◽  
Vol 35 (7) ◽  
pp. 945-950 ◽  
Author(s):  
M. C. Healey
Keyword(s):  
Key Words ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Northern Canada ◽  
Average Fecundity ◽  
Individual Fecundity

This report considers the possibility that exploited populations of lake whitefish (Coregonus clupeaformis) and lake trout (Salvelinus namaycush) may show increased individual fecundity. Average fecundity of both species in three exploited lakes varied significantly between 1972 and 1976, while fecundity in an adjacent unexploited lake did not vary. Changes in the fecundity of whitefish and trout in the exploited lakes were not clearly related to the pattern and intensity of exploitation, but fecundity of both species increased in all exploited lakes after exploitation, with trout showing the greater response. Key words: fecundity, lake whitefish, lake trout, exploitation, northern Canada

Long-Term Effects of Diet on the Biology of the Lake Trout and the Fishery in Lake Opeongo, Ontario

1970 ◽  
Vol 27 (1) ◽  
pp. 125-146 ◽  
Author(s):  
N. V. Martin
Keyword(s):  
Lake Trout ◽  
Feeding Activity ◽  
Salvelinus Namaycush ◽  
Point Of View ◽  
Average Weight ◽  
Coregonus Clupeaformis ◽  
Long Term Effects ◽  
Food Content ◽  
Coregonus Artedii

From 1936 to 1965 food content was examined in 17,171 Lake Opeongo lake trout (Salvelinus namaycush). The diet is analysed from the point of view of frequency of occurrence of foods, their weight, feeding activity of trout, size of trout and size of food, and seasonal and annual changes in food habits.In the late 1940's and early 1950's perch, Perca flavescens, largely disappeared from the diet. The lake trout initially turned to lake whitefish, Coregonus clupeaformis, and then to the cisco, Coregonus artedii, introduced into Lake Opeongo in 1948.As a result of these dietary changes lake trout are now heavier and rate of growth has improved. Age and size at maturity is later and there are fewer infertile fish. Egg counts, egg size, and ovary weights are now greater, particularly in the medium-sized lake trout.In the fishery the average weight of individual trout taken has almost doubled. About 25% more of the immature stock is exploited by the recent fishery. The harvest and catchability of lake trout has remained generally constant on a numerical basis but show an improvement on a poundage basis in the more recent years. The possible effects of these changes on the character of the fishery are discussed.

Optimal Use of Creel Survey Data in Assessing Population Behaviour: Lake Opeongo Lake Trout (Salvelinus namaycush) and Smallmouth Bass (Micropterus dolomieui), 1936–83

1987 ◽  
Vol 44 (S2) ◽  
pp. s229-s238 ◽  
Author(s):  
B. J. Shuter ◽  
J. E. Matuszek ◽  
H. A. Regier
Keyword(s):  
Lake Trout ◽  
Total Mortality ◽  
Salvelinus Namaycush ◽  
Fish Population ◽  
Smallmouth Bass ◽  
Fishing Mortality ◽  
Assessment Data ◽  
Creel Survey ◽  
Micropterus Dolomieui ◽  
Independent Assessment

Creel survey and independent assessment data on the lake trout (Salvelinus namaycush) and smallmouth bass (Micropterus dolomieui) populations of Lake Opeongo were evaluated. Annual estimates of total mortality, fishing mortality, and abundance were generated for each population over the period 1936–83. Large variations in survey efficiency, angler efficiency, fishing mortality, and abundance were identified over this period. We argue that a creel survey, which is expected to provide reliable information on fish population dynamics, requires an overall study design which includes collection of data on the number and relative efficiency of different kinds of anglers and periodic assessment studies aimed at providing independent checks on both survey effectiveness and population behaviour.

Bomb radiocarbon chronologies in the Arctic, with implications for the age validation of lake trout (Salvelinus namaycush) and other Arctic species

2008 ◽  
Vol 65 (4) ◽  
pp. 733-743 ◽  
Author(s):  
Steven E Campana ◽  
John M Casselman ◽  
Cynthia M Jones
Keyword(s):  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Abrupt Onset ◽  
Arctic Lakes ◽  
The Arctic ◽  
Oceanic Circulation ◽  
Age Validation ◽  
Interpretation Criteria ◽  
Bomb Radiocarbon ◽  
Radiocarbon Chronology

Radiocarbon generated by atmospheric testing of nuclear weapons (bomb radiocarbon) produced a strong signal with an abrupt onset in the 1950s, which serves as a dated marker for tracing oceanic circulation and confirming age in animals forming growth bands. Here, we report the first prebomb and postbomb radiocarbon chronologies for marine and freshwater environments in the Canadian Arctic, extend the radiocarbon chronology for the northwest Atlantic Ocean, and use the onset of the bomb signal to validate our age interpretations of lake trout (Salvelinus namaycush) in Arctic lakes. Both surface and deepwater Arctic chronologies became detectable on or around 1958, similar to the year of onset elsewhere in the world. In contrast, the freshwater Arctic chronology increased sharply in 1957, with a peak value sixfold higher than the adjacent marine environment. The radiocarbon content of the adult otolith core validated our age interpretation criteria for Arctic lake trout to an age of at least 50 years. Otolith growth in such slow-growing fish was so low as to be unresolvable under conventional examination with a dissecting microscope. With these new radiocarbon reference chronologies, age validation of a large number of Arctic organisms should now be possible.

scholarly journals Genome Sequences of Shewanella baltica and Shewanella morhuae Strains Isolated from the Gastrointestinal Tract of Freshwater Fish

2018 ◽  
Vol 6 (25) ◽  
Author(s):  
Daniel Castillo ◽  
Lone Gram ◽  
Frank E. Dailey
Keyword(s):  
Gastrointestinal Tract ◽  
Freshwater Fish ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Coregonus Clupeaformis ◽  
Genome Sequences ◽  
Content Type ◽  
Niche Adaptation ◽  
Specific Species ◽  
Shewanella Baltica

ABSTRACT We present here the genome sequences of Shewanella baltica strain CW2 and Shewanella morhuae strain CW7, isolated from the gastrointestinal tract of Salvelinus namaycush (lean lake trout) and Coregonus clupeaformis (whitefish), respectively. These genome sequences provide insights into the niche adaptation of these specific species in freshwater systems.

Anadromy in Arctic populations of lake trout (Salvelinus namaycush): otolith microchemistry, stable isotopes, and comparisons with Arctic char (Salvelinus alpinus)

2010 ◽  
Vol 67 (5) ◽  
pp. 842-853 ◽  
Author(s):  
Heidi K. Swanson ◽  
Karen A. Kidd ◽  
John A. Babaluk ◽  
Rick J. Wastle ◽  
Panseok P. Yang ◽  
...  
Keyword(s):  
Lake Trout ◽  
Salvelinus Alpinus ◽  
Salt Water ◽  
Salvelinus Namaycush ◽  
Otolith Microchemistry ◽  
Scientific Data ◽  
Arctic Char ◽  
Arctic Lakes ◽  
Size Dependent ◽  
The Family

In the family Salmonidae, lake trout ( Salvelinus namaycush ) are considered the least tolerant of salt water. There are, however, sporadic reports of lake trout in coastal, brackish habitats in the Canadian Arctic. Otolith microchemistry analyses conducted on lake trout and Arctic char ( Salvelinus alpinus ) from four Arctic lakes in the West Kitikmeot region of Nunavut, Canada, revealed that 37 of 135 (27%) lake trout made annual marine migrations. Anadromous lake trout were in significantly better condition (K = 1.17) and had significantly higher C:N ratios (3.71) than resident lake trout (K = 1.05 and C:N = 3.34). Anadromous lake trout also had significantly higher δ15N (mean = 16.4‰), δ13C (mean = –22.3‰), and δ34S (mean = 13.43‰) isotope ratios than resident lake trout (means = 12.84‰, –26.21‰, and 1.93‰ for δ15N, δ13C, and δ34S, respectively); results were similar for Arctic char and agree with results from previous studies. Mean age of first migration for lake trout was 13 years, which was significantly older than that for Arctic char (5 years). This could be a reflection of size-dependent salinity tolerance in lake trout, but further research is required. These are the first detailed scientific data documenting anadromy in lake trout.

Sign in / Sign up

Export Citation Format

Share Document